1. Field of the Invention
The present invention relates to a hog ring clamping device which clamps a hog ring such as a C ring used for attaching a covering material to a member such as a spring of a sheet of a vehicle.
2. Description of the Prior Art
In a conventional C ring clamping device, a magazine for loading C rings is attached to a clamping device main body. The clamping device main body has jaws to deform the C ring, a pneumatic cylinder to open/close the jaws and a directional control valve connected to the pneumatic cylinder. A grip is provided in a lower portion of the clamping device main body. The grip includes an air supply passage connected to an air feed port of the directional control valve. The grip includes a first air discharge passage connected to a first discharge port of the directional control valve. The first air discharge passage opens in a lower portion of the grip. Further, the clamping device main body has a second air discharge passage connected to a second discharge port of the directional control valve. The second air discharge passage opens in a back portion of the clamping device main body.
In the C ring clamping device, the pneumatic cylinder is expanded and contracted by operating the directional control valve, the jaws are opened and closed, the C ring is deformed, and matters to be clamped are clamped by the deformed C ring.
However, as the C ring clamping device requires a compressed air supply device, the place where the C ring clamping operation can be performed is limited. Further, the C ring clamping device generates large air discharge noise every time the directional control valve is operated to deteriorate the working environment of a place where the C ring clamping device is used for clamping work using C rings.